Storage case for tape cassette

ABSTRACT

A storage case for a tape cassette, having a storage section for storing a magnetic tape cassette therein, a lid section having outer plates surrounding the storage section, a hinge plate section for connecting the lid section to the storage section so that the lid section can be opened and closed, an engagement portion formed on an outer side surface of an outer plate of the lid section, a locking plate base end portion formed at the edge of the storage section which is on the opposite side to the hinge plate section thereof, and a locking plate supported on the locking plate base end portion via a hinge portion and engageable with the engagement portion, wherein the locking plate base end portion is formed so that this base end portion is recessed from a position on the edge toward the side of the storage section.

This application is based on Japanese Patent application JP 2004-175408, filed Jun. 14, 2004 and JP 2004-183797, filed Jun. 22, 2004, the entire contents of which are hereby incorporated by reference. This claim for priority benefit is being filed concurrently with the filing of these applications.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to a tape cassette storage case used to store a magnetic tape cassette therein and protect the same.

2. Description of the Related Art

For example, a tape cassette used in a broadcasting station has large dimensions and large weight as compared with a commercially available video tape cassette. Therefore, when the tape cassette falls, an impact imparted thereto is large, so that the impact causes the tape cassette to be damaged. Under the circumstances, the tape cassette is stored in a special storage case of a synthetic resin while the tape cassette is kept in custody or transported, for the purpose of preventing the tape cassette from being damaged due to the impact.

A storage case for a tape cassette, including a storage section, a lid section and a hinge is known as an example of such a related art storage case for a tape cassette (refer to, for example, JP-A-2002-179176).

FIG. 8 is a drawing showing a related art storage case for a tape cassette.

As shown in FIG. 8, a related art storage case 70 for a tape cassette has a hard type case body, which includes a storage section 71 having four side walls 72, a lid section 73 having three side walls 74, and a connecting portion 79 which has hinges 77, 78 by which a bottom plate 75 of the storage section 71 and a top plate 76 of the lid section 73 are connected together, and which forms one side wall of the lid section 73 when the lid section 73 is closed.

In an inner portion of the lid section 73, a front side wall 74, which is on the opposite side of the connecting portion 79, is provided at both end portions thereof with side wall locking portions 80 provided with hooked portions 81 are formed. The hooked portions 81 are engaged with engagement holes 82, when the lid section 73 is closed, formed in a side wall 72 of the storage section 71.

The storage case 70 for a tape cassette is provided at a front side opposite to the side of the connecting portion 79 with a side locking portion 84 on which an outer circumferential edge portion 83 is cut off. The side locking portion 84 is connected to the bottom plate 75 of the storage section 71 via hinges 85, and provided with a flap plate 86. When the side wall 74 of the closed lid section 73 is superposed, hooked portions 87 formed on the flap plate 86 are engaged with engagement portions (not shown) on an outer surface of the side wall 74 of the lid section 73 and locked.

However, when the storage case 70 for a tape cassette with the side locking portion 84 locked up falls, an impact of the fall is imparted to the side locking portion 84 to cause the side locking portion 84 to be bent, so that the side locking portion 84 is disengaged from the engagement portions in some cases. As a result, the magnetic tape cassette held in the storage case 70 springs out therefrom when the storage case falls, and is damaged in some cases. The present invention has been made in view of the above-mentioned facts.

SUMMARY OF THE INVENTION

An object of the invention is to provide a storage case for a tape cassette, capable of preventing more reliably the lock from being disengaged when the storage case falls down.

<First Aspect>

A storage case for a tape cassette, provided with a storage section for storing a magnetic tape cassette therein, a lid section having outer plates surrounding the storage section, a hinge plate section for connecting the lid section to the storage section so that the lid section can be opened and closed, an engagement portion formed on an outer surface of one of the outer plates of the lid section, a locking plate base end portion formed at an edge of the storage section which is on an opposite side to the hinge plate section thereof, and a locking portion supported on the locking plate base end portion via a hinge portion and engageable with the engagement portion, wherein the locking plate base end portion is formed so that the base end portion is recessed from other positions on an edge thereof toward a side of the storage section.

According to this storage case for a tape cassette, the locking plate base end portion formed on the edge of the storage section is provided in the part of this base end portion which is recessed from the other positions on the edge toward the storage section. Owing to this structure, even though an impact is imparted to the edge of the storage section when the storage case for a tape cassette, the locking plate of which is engaged with the engagement portion, falls down, the impact can be prevented from being imparted directly to the locking plate base end portion. Therefore, the occurrence of deflection of the locking plate ascribed to the impact 6 of the fall of the storage case can be prevented, so that the locking plate does not disengage from the engagement portion.

In the storage case for a tape cassette, the locking plate base end portion is preferably formed by cutting off the corner (c chamfer processing). It is also preferable that the locking plate base end portion be formed by providing a stepped portion in a part of the edge of the storage section.

When the storage case for a tape cassette is formed in this manner, the locking plate base end portion can be provided in a recessed position toward the side of the storage section by a simple structure. According to such a structure, the occurrence of an undercut can be avoided when the storage case for a tape cassette is integrally molded in a metal mold.

<Second Aspect>

A storage case for a tape cassette, provided with a storage section for storing a tape cassette therein, a lid section having outer plates surrounding the storage section, a hinge plate section for connecting the lid section to the storage section so that the lid section can be opened and closed, an engagement portion formed on an outer surface of one of the outer plates of the lid section, a locking plate base end portion formed at an edge of the storage section which is on an opposite side to the hinge plate section, and a locking plate supported on the locking plate base end portion via a hinge portion and engageable with the engagement portion, wherein the locking plate base end portion is provided with a rib in contact with the one of the outer plates of the lid section when the locking plate is engaged with the engagement portion.

According to this storage case for a tape cassette, the condition of the ribs, which are provided on the locking plate base end portion, in contact with the outer plate is maintained when the engagement portion and locking plate of the lid section are engaged with each other. As a result, when the storage case for a tape cassette falls with the locking plate and lid section in the engaged state, the locking plate base end portion is supported on the rib even though a falling impact is imparted to the locking plate base end portion. Therefore, the deflection of the locking plate can be prevented. Since the occurrence of deflection of the locking plate base end portion is prevented, the imparting of a deformation load ascribed to the deflection of the locking plate connected to the locking plate base end portion is prevented, so that the disengagement of the locking plate from the engagement portion of the lid section can be prevented. Accordingly, since the locking plate is rendered difficult to be disengaged in spite of an impact imparted thereto when the storage case falls, the occurrence of the springing out of the magnetic tape cassette therefrom, which causes the same to be damaged, is prevented.

According to the present invention, a storage case for a tape cassette, capable of preventing the lock from being disengaged when the storage case falls, can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an external appearance of one embodiment of the storage case for cassettes according to the present invention.

FIG. 2 is a sectional view of parts around the locking plate of a first embodiment of the first aspect of the storage case for a tape cassette shown in FIG. 1.

FIG. 3 is a sectional view of parts around the locking plate showing a second embodiment of the first aspect of the storage case for a tape cassette according to the present invention.

FIG. 4 is a sectional view showing the state of the storage case for a tape cassette of FIG. 1 taken along the line A-A when the lid section is not yet closed.

FIG. 5 is a sectional view showing the state of the storage case for a tape cassette of FIG. 1 taken along the line A-A when the lid section is closed and the locking plate is not yet locked.

FIG. 6 is a sectional view showing the state of the storage case for a tape cassette of FIG. 1 taken along the line A-A when the lid section is closed and the locking plate is locked.

FIG. 7 is a drawing of the storage case for a tape cassette of FIG. 1 taken in the direction of an arrow B therein.

FIG. 8 is a drawing showing the opened state of the related art storage case for a tape cassette.

DETAILED DESCRIPTION OF THE INVENTION

Examples of embodiments of the present invention will be described in detail on the basis of the drawings. FIG. 1 is a perspective view showing one embodiment of the storage case for a tape cassette according to the present invention. FIG. 2 is a sectional view of the storage case for a tape cassette of FIG. 1 taken along the line A-A therein.

As shown in FIG. 1, a storage case 10 for a tape cassette includes a storage section 11 for storing a magnetic tape cassette C therein, a lid section 12 having outer plates 13, 14, 15 surrounding the storage section 11, a hinge plate section 16 for connecting the storage section and lid section together so that the storage section and lid section can be opened and closed, and a locking plate 17 connected to the storage section 11 via a hinge portion 18 in openable and closable state, all of which are integrally molded. The storage case 10 for a tape cassette is molded of a polymeric material, such as polypropylene (PP).

On an outer edge portion of a bottom plate 19 of the storage section 11, circumferential plates 20, 21, 22, 23 arranged so as to surround a circumference of the bottom plate are provided in a vertically extending state. The circumferential plate 20 is provided on a front side of the storage section 11, and the circumferential plate 21 on a rear side thereof, the circumferential plates 22, 23 being provided on left and right sides of the storage section 11, respectively. In central regions of these circumferential plates 20, 21, 22, 23, cutout portions forming recesses 24, 25, 26, 27 are provided so that the height of the circumferential plates decreases.

The storage section 11 is provided on the central portion of the bottom plate 19 thereof with a pair of reel locking ribs 28. Each of the reel locking ribs 28 has a cylindrical shape divided into a plurality of parts in the circumferential direction thereof due to slits formed therein. A take-up hub (not shown) provided on the magnetic tape cassette C is inserted into the reel locking rib 28, and the magnetic tape cassette C is thereby positioned on the storage section 11.

The storage section 11 is provided in the front surface at both sides of the recess 24 of the circumferential plate 20 with first engagement portions 30. The outer plate 13 on the opposite side to the hinge plate section 16 is provided at both end portions of an inner surface thereof with first locking portions 31. The first engagement portions 30 and first locking portions 31 are formed so that, when the lid section 12 is closed, the first engagement portions 30 and first locking portions 31 are engaged with each other.

The lid section 12 is provided on circumferential edge portions of its top plate 32 with outer plates 13, 14, 15 arranged vertically so that the outer plates 13 surround the three sides of the circumference thereof. The outer plates 13, 14, 15 are formed so that the outer plate 13 is positioned on the front side of the storage section 11 with the outer plates 14, 15 positioned on both side surfaces thereof when the lid section 12 is put on the storage section 11.

In the lid section 12, the inner surfaces of the outer plates 14, 15 are provided with square pole type bosses 33 of a large height. The square bosses 33 are provided so that the square bosses 33 are positioned between the outer surfaces of the circumferential plates 22, 23 of the storage section 11 and the inner surface of the outer plates 14, 15 when the lid section 12 is closed with respect to the storage section 11. The square bosses 33 are adapted to guide the closed lid section 12 so that the lid section 12 is in proper positions.

The hinge plate section 16 is formed in the shape of a plate between the storage section 11 and lid section 12. The edge portions of the hinge plate section 16 which are connected to the storage section 11 and lid section 12 are provided with hinges 34, 35. One hinge 34 is connected to one side of the bottom plate 19 of the storage section 11, and the other 35 to one side of the top plate 32 of the lid section 12.

A plate locking plate 17 of a trapezoidal shape is connected to a substantially central portion of the edge 40 of the circumferential plate 20 of the storage section 11. The locking plate 17 is provided at a front end portion thereof with a second locking portion 44.

A horizontally extending second engagement portion (engagement portion) 36 set up on the outer surface of the outer plate 13 is formed on the lid section 12.

In the embodiment of the first aspect of the present invention, a circumferential plate 20 of the storage section 11 is provided with an edge portion 40 projecting horizontally along an outer surface of a lower end portion thereof as shown in FIG. 2. The edge 20 is provided at substantially the central region thereof with a horizontal extension 41 extending from substantially the central region of the edge, and a locking plate base end portion 42 extending diagonally upward at an angle of about 45° from the front end portion (left end portion in FIG. 2) of the extension 41.

In this embodiment, the locking plate base end portion 42 has an outer surface whose corner is cut off so that the base end portion 42 is inclined at an angle of 45° in the left upward direction. Thus, the locking plate base end portion 42 is recessed from a position 43 on the edge 40 of the circumferential plate 20 toward the side of the storage section 11.

The locking plate 17 is connected via the hinge portion 18 to the end portion which is on the opposite side to the extension 41 in the locking plate base end portion 42. The locking plate 17 is formed so that the locking plate can be inclined and folded toward the circumferential plate 20 as shown by an arrow R in FIG. 2. The locking plate 17 is provided at a front end portion thereof with a second locking portion 44 engageable with the second engagement portion 36 of the lid section 12 when the locking plate is folded to the side of the circumferential plate 20.

In the storage case 10 for a tape cassette, the lid section 12 is closed with respect to the storage section 11 in the direction of an arrow in FIG. 1 to cause the first engagement portions 30 to be engaged with the first locking portions 31 respectively. When the locking plate 17 is then turned in the upward direction in FIG. 1 via the hinge portion 18, the second locking portion 44 of the locking plate 17 is engaged with the second engagement portion of the lid section 12 and locked. Namely, the storage case has a so-called double locking structure.

In the storage case for a tape cassette in this embodiment, the locking plate base end portion 42 of the edge 40 of the storage section 11 connected to the locking

The locking plate 17 is connected via the hinge portion 18 to the end portion-which is on the opposite side to the extension 41 in the locking plate base end portion 42. The locking plate 17 is formed so that the locking plate can be inclined and folded toward the circumferential plate 20 as shown by an arrow R in FIG. 2. The locking plate 17 is provided at a front end portion thereof with a second locking portion 44 engageable with the second engagement portion 36 of the lid section 12 when the locking plate is folded to the side of the circumferential plate 20.

In the storage case 10 for a tape cassette, the lid section 12 is closed with respect to the storage section 11 in the direction of an arrow in FIG. 1 to cause the first engagement portions 30 to be engaged with the first locking portions 31 respectively. When the locking plate 17 is then turned in the upward direction in FIG. 1 via the hinge portion 18, the second locking portion 44 of the locking plate 17 is engaged with the second engagement portion of the lid section 12 and locked. Namely, the storage case has a so-called double locking structure.

In the storage case for a tape cassette in this embodiment, the locking plate base end portion 42 of the edge 40 of the storage section 11 connected to the locking plate 17 is formed so that the locking plate base end portion 42 is recessed toward the storage section 11 with respect to the part 43 of the edge 40. Therefore, even when an impact is imparted to the edge 40 in the direction shown by an arrow B in FIG. 2 at the time of fall of the storage case 10 for a tape cassette with the locking plate 17 engaged with the engagement portion 36 of the lid section 12, the locking plate base end portion 42 can be prevented from receiving the impact directly. This enables both the occurrence of deflection of the locking plate 17 ascribed to the impact at the time of fall of the storage case, and the occurrence of the disengagement of the locking plate 17 from the engagement portion 36 to be prevented. Therefore, it is possible to render the locking difficult to be disengaged when the storage case for a tape cassette falls, and prevent the magnetic tape cassette C from springing out of the storage section 11 and being damaged.

FIG. 3 is a sectional view showing the parts around the locking plate in the second embodiment of the first aspect of the storage case for a tape cassette according to the present invention.

in a storage case 50 for a tape cassette, an edge 60 of a circumferential plate 20 is provided as shown in FIG. 3 with a vertical portion 61 set up substantially perpendicularly from an end portion of an extension 51, and a horizontal portion 62 extending horizontally from an upper end of the vertical portion 61. A locking plate 17 is connected via a hinge portion 18 to the end portion of the horizontal portion 62 which is on the opposite side to the vertical portion 61. In the storage case for a tape cassette 50 of this embodiment, the vertical portion 61 and horizontal portion 62 form a locking plate base end portion.

In the edge 60, the vertical portion 61 and horizontal portion 62 form a stepped portion which constitutes a recess in section on the inner side of the storage section 11. The vertical portion 61 and horizontal portion 62 are provided in a recessed position toward the storage section 11 with respect to the portion 63 of the edge 60 of the circumferential plate 20.

The construction and operations of the other parts are identical with those of the corresponding parts of the above-described the first embodiment.

To be concrete, the edge 60 of storage section 11 in the storage case 50 for a tape cassette in the embodiment of the first aspect is formed so that the edge 60 forms a sectionally recessed stepped portion on the inner side of the storage section 11 by the vertical portion 61 and horizontal portion 62. Also, the edge 60 of storage section has such a construction that the vertical portion 61 and horizontal portion 62 is recessed toward the storage section 11 with respect to the portion 63 of the edge 60 of the circumferential plate 20.

Therefore, even when the storage case 50 for a tape cassette falls with a second locking portion 44 of the locking plate 17 engaged with the second engagement portion of the lid section 12, it is possible to prevent an impact occurring due to the fall of the storage case from being imparted directly to the vertical portion 61 and horizontal portion 62 of the storage section 11. Accordingly, the impact caused by the fall of the storage case is not transmitted to the locking plate 17, and the disengagement of the locking plate 17 from the second engagement portion 44 due to the deflection of the locking plate 17 can be reliably prevented.

The present invention is not limited to the above-described embodiments. As far as the locking plate base end portion is recessed from other portions of the edge of the storage case toward the side of the storage section, suitable modifications and improvements can be made. The locking plate base end portion may have a chamfered portion which is rounded off (R chamfer processing).

Then, an example of one embodiment of a second aspect of the present invention will now be described on the basis of the drawings. FIGS. 4 to 6 are sectional views taken along the line A-A in FIG. 1 showing the construction of the storage case for a tape cassette shown in FIG. 1, wherein FIG. 4 shows the state when a lid section is not yet closed; FIG. 5 the state when the lid section is closed and a locking plate is not yet engaged; and FIG. 6 the state when the lid section is closed and the locking plate is engaged, FIG. 7 being a partial enlarged view of the storage case for a tape cassette shown in FIG. 1.

As shown in FIGS. 4, 5 and 6, a circumferential plate 20 of a storage section 11 is provided with an edge 40 projected along an outer surface of a lower end portion thereof. The edge 40 is provided at a substantially central portion thereof with a horizontal extension 41, and a locking plate base end portion 42 set up at an angle of about 45° in the leftward diagonal direction from an end portion of the extension 41. The locking plate base end portion 42 is recessed in section in FIG. 4 toward an inner side of the storage section 11 with respect to the portion 43 in the edge 40 of the circumferential plate 20.

The locking plate 17 is connected to a front end portion of the locking plate base end portion 42 via a hinge portion 18. The locking plate 17 is formed so that the locking plate can be folded toward the circumferential plate 20 by turning the same around the hinge portion 18. The lid section 12 can be locked by engaging a lower end section of a second engagement portion 36 with a second locking portion of the locking plate 17 when the lid section 12 is closed with respect to the storage section 11.

In the storage case 10 for a tape cassette, the lid section 12 is closed with respect to the storage section 11 to cause the first locking portions 31 to be engaged with the first engagement portions 30 respectively and locked. When the locking plate 17 is then set in the upward direction in FIG. 1 via the hinge portion 18, the second locking portion 44 of the locking plate 17 is engaged with the second engagement portion 36 and locked. Namely, the storage case has a so-called double locking structure.

As shown in FIG. 4 and FIG. 7, the locking plate base end portion 42 is provided with a pair of ribs 45 so that the ribs 45 project in parallel with the extension 41 toward the circumferential plate 20 of the storage section 11. These two ribs have the same shape, and are provided in a mutually spaced manner in the longitudinal direction of the hinge portion 18. In this embodiment, the ribs 45 are provided so that the ribs contact the outer surface of the outer plate 13 of the lid section 12 when the lid section 12 is closed with respect to the storage section 11.

The operation of the ribs 45 will now be described concretely with reference to FIGS. 4, 5 and 6,

In order to close (put in a closed state) the lid section 12 with respect to the storage section 11, the lid section 12 is moved in the direction of an arrow as shown in FIG. 4. The first locking portions 31 provided on an inner surface of the outer plate 13 of the lid section 12 is then engaged as shown in FIG. 6 with the first engagement portions 30 provided on an outer surface of the circumferential plate 20 on the front side of the storage section 11. During this time, the front end section 45 a of a rib 45 provided on an inner surface of the locking plate base end portion 42 contacts the outer surface of the outer plate 13 of the lid section 12.

In order to put the closed lid section 12 in a locked state, the locking plate 17 is folded in the direction of an arrow as shown in FIG. 5, to cause a second locking portion 44 of the locking plate 17 to be engaged with a second engagement portion 36 provided on the outer surface of the outer plate 13 of the lid section 12 as shown in FIG. 6. When a second engagement portion 36 of the lid section 12 and a second locking portion 44 of the locking plate 17 are engaged with each other to put the lid section 12 in a locked state, the condition of the front end section 45 a of the rib 45 of the locking plate base end portion 42 in contact with the outer surface of the outer plate 13 of the lid section 12 is maintained.

This embodiment is formed so that the rib 45 contacts at only the front end portion 45 a thereof with the outer plate 13 of the lid section 12. The same embodiment has only to be so formed that at least a part of the rib 45 contacts the outer plate 13 of the lid section 12.

According to the storage case 10 for a tape cassette in this embodiment, the condition of the rib 45, which are provided on the locking plate base end-portion 42, in contact with the outer surface of the outer plate 13 of the lid section 12 is maintained when the engagement portion 36 of the lid section 12 and the locking portion 44 of the locking plate 17 are engaged with each other. As a result, when the storage case 10 for a tape cassette falls with the locking plate 17 and lid section 12 engaged with each other, the occurrence of deflection of the locking plate base end portion 42 is prevented since the locking plate base end portion 42 is supported on the rib 45 from the inner surface thereof even when an impact due to the fall of the storage case is imparted to the locking plate base end portion 42 in the direction shown by an arrow in FIG. 6. Since the occurrence of deflection 6 in the locking plate base end portion 42 is prevented, the imparting of a load, which occurs due to the deformation ascribed to the deflection of the locking plate 17 connected to the locking plate base end portion, is prevented. Therefore, the locking portion 44 of the locking plate 17 can be prevented from disengaging from the engagement portion 36. This makes it possible to render the locking plate 17 difficult to be disengaged due to the impact occurring when the storage case falls, and to prevent the tape cassette C from being sprung out of the storage section 11 and damaged.

In this embodiment, a pair of ribs 45 are provided on the locking plate base end portion 42 as shown in FIG. 7 but the construction of the ribs 45 is not limited to this. For example, a single rib 45 or not smaller than three ribs 45 may be provided as long as the rib 45 is formed as far as the rib 45 can contact the outer plate 13 of the lid section 12 with the lid section 12 locked. The shape of the rib 45 may be varied suitably as long as at least a part of the rib 45 contacts the lid section 12 with the lid section 12 locked.

It is preferable that a predetermined size of clearance be provided between the ribs 45 of the locking plate base end portion 42 and extension 41. When this structure is employed, the locking plate base end portion 42 can be bent suitably when the locking portion 44 of the locking plate 17 is locked up with respect to and disengaged from the engagement portion 36 of the lid section 12. Therefore, the inconvenience of difficulty in engaging the locking plate 17 with the lid section 12 due to the utter impossibility of bending the locking plate base end portion 42 due to the provision of the rib 45 can be eliminated. In order to disengage the engaged locking plate 17, the locking plate base end portion 42 is bent suitably. This makes it easy to disengage the lock plate 17, and the convenience of use of the storage case is improved. It is preferable that the predetermined size of the clearance between the rib 45 and extension 41 be 0.2 mm to 1 mm.

The present invention is not limited to the above-described embodiments and aspects, and suitable modifications and improvements can be made.

For example, the shape of the locking plate 17 is not limited to the trapezoidal shape in plan in these embodiments. This portion may have a square shape and a semicircular shape. 

1. A storage case for a tape cassette, comprising: a storage section that stores a magnetic tape cassette therein, a lid section having outer plates surrounding the storage section, a hinge plate section that connects the lid section to the storage section so that the lid section can be opened and closed, an engagement portion on an outer surface of one of the outer plates of the lid section, a locking plate base end portion at an edge portion of the storage section which is on an opposite side to the hinge plate section, the locking plate base end portion being recessed from other portions of the edge portion toward a side of the storage section and a locking plate supported on the locking plate base end portion via a hinge portion and engageable with the engagement portion.
 2. The storage case according to claim 1, wherein the locking plate base end portion has a chamfered portion which is cut off so that a part of the locking plate base end portion is inclined at an angle in an upward direction.
 3. The storage case according to claim 2, wherein the angle is 45°.
 4. The storage case according to claim 1, wherein the locking plate base end portion has a stepped portion.
 5. The storage case according to claim 4, wherein the stepped portion comprises a horizontal portion and a vertical portion.
 6. The storage case according to claim 5, wherein the locking plate is connected to an end portion of the horizontal portion and the edge portion of the storage section is connected to an end portion of the vertical portion.
 7. The storage case according to claim 1, wherein the locking plate base end portion has a chamfered portion which is rounded off.
 8. The storage case according to claim 1, wherein the storage section comprises an engagement portion in an outer surface of at least one of circumferential plates, and the lid section comprises a locking plate in an inner surface of at least one of the outer plates which is engaged with the engagement portion of the storage section.
 9. A storage case for a tape cassette, comprising: a storage section that stores a magnetic tape cassette therein, a lid section having outer plates surrounding the storage section, a hinge plate section that connects the lid section to the storage section so that the lid section can be opened and closed, an engagement portion on an outer surface of one of the outer plates of the lid section, a locking plate base end portion at an edge portion of the storage section which is on an opposite side to the hinge plate section, and a locking plate supported on the locking plate base end portion via a hinge portion and engageable with the engagement portion, wherein the locking plate base end portion is provided with at least one rib in contact with the one of the outer plates of the lid section when the locking plate is engaged with the engagement portion.
 10. The storage case according to claim 9, wherein the at least one rib contacts the one of the outer plates in a front end portion thereof.
 11. The storage case according to claim 9, wherein the at least one rib consists of a pair of ribs.
 12. The storage case according to claim 9, wherein a clearance is provided between the rib and an extension of the edge portion of the storage section.
 13. The storage case according to claim 12, wherein the clearance has a size of 0.2 mm to 1 mm.
 14. The storage case according to claim 9, wherein the locking plate base end portion is recessed from other portions of the edge portion toward a side of the storage section.
 15. The storage case according to claim 14, wherein the locking plate base end portion has a chamfered portion which is cut off so that a part of the locking plate base end portion is inclined at an angle in an upward direction.
 16. The storage case according to claim 15, wherein the angle is 45°.
 17. The storage case according to claim 14, wherein the locking plate base end portion has a stepped portion.
 18. The storage case according to claim 17, wherein the stepped portion comprises a horizontal portion and a vertical portion.
 19. The storage case according to claim 18, wherein the locking plate is connected to an end portion of the horizontal portion and the edge portion of the storage section is connected to an end portion of the vertical portion.
 20. The storage case according to claim 1, wherein the locking plate base end portion has a chamfered portion which is rounded off. 